Automatic sander and leveling machine



July 14, 1942. D. PRONOVQST AUTOMATIC SANDER AND LEVELING MACHINE Filed July 31, 1941 2 Sheets-Sheet 2 Patented July 14, 1942 AUTOIWATIC SANDER AND LEVELING MACHINE David Pronovost, Rosemont, Montreal, Quebec,

. Canada Application July 31, 1941, Serial No. 404,884 In Canada July 31, 1940 10 Claims.

Another object is to provide a means for applying more intense abrasion at any particular point across the width of the head, and this is accomplished essentially by means of a slidable and adjustable weight on the head.

Another object of the invention is to provide a means for removingexceptionally high spots before treating the principal surface. This means consists of adjustable legs on the sander head whereby the latter may be lifted slightly off the fioor in order to operate on the high spots. In such an operation the head is gradually lowered until finally the main surface is engaged thereby.

The carriage carries an electric motor for propulsion and another motor for actuating the mechanism. Through suitable gearing, this motor finally rotates a lever or a pair of levers. 3

Operating rods extend from the sander head and are jcurnalled respectively to the levers, so that on rotation of the latter, the head is oscillated on the surface and also tilted. In this connection, the abrasive surface of the head is convex, with the result that all parts of the latter are broughtinto contact with the surface on the tilting movement.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings in which:

Figure l is the side elevation of the device;

Figure 2 is a top plan view thereof;

Figure 3 is a detail longitudinal section of the sander;

Figure 4 is a front end view;

Figure 5 is a detail elevation illustrating the various positions of the sander;

Figure 6 is a detail longitudinal section of the sander;

Figure '7 is an enlarged detail of Figure 6, and

Figure 8 is another side elevation of the sander, showing an attachment for removing unusually rough spots.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

Although the entire apparatus is known as a sander and leveler, it may for convenience be considered as comprising two parts, the carriage carrying the actuating mechanism, and the sander or operating head. The sander head comprises a base I adapted to extend across the width of a bowling alley, as shown in Figure 4, and having a substantially U-shape as shown in Figure 1 for the purpose of receiving a pair of uprights 2 near the ends. The lower surface of the base I is convex or rounded as indicated by the numeral 3 and is formed with V-shaped grooves 4 at the edges of the convex surface, as shown more clearly in Figure 7. The abrasive material is illustrated in the form of a sheet 5 engaging the convex surface and secured in the grooves by blocks 6 which in turn are held by bolts 1 extending the lengthwise of the machine, as shown in Figure 6. The sheet forming the abrasive may be of suitable material such as sand paper, steel wool, rough sheet metal or the like and may be replaced for a polishing operation by a material such as felt.

A weight 8 is slidably mounted in a channel 9 formed transversely in the base I (the transverse and longitudinal directions being those of the bowling alley or of the entire machine) The ends of the weight are formed as uprights It] and are held at their upper extremities by a rod ill mounted in the uprights 2. A pair of operating bars II are fastened to the sander head and extend longitudinally and rearwardly therefrom, as shown in Figures 1 and 2, to an operating mechanism which will presently be described.

As shown more clearly in Figure 4, the sander head rests transversely on. the bowling alley from edge to edge of the latter. The movement along the alley is guided by adjustable rods 13 extending from the ends of the base I and fitted with rollers l4 riding along the alley partitions or gutter walls I5.

The desired movement of the sander head is imparted by mechanism mounted on the carriage l6 which in turn rides on wheels or rollers 11. The carriage is propelled along the alley by an electric motor I8. The motor is connected by a belt l9 to a counter-shaft 20, and the latter to another shaft 2| through a belt 22 and variable speed pulleys 23. The shaft 2| is finally connected by a belt 24 to a drive shaft 25 formed at its ends with worms 26 meshing with worm gears 21 on the axis 28 of opposed wheels l1.

Another motor 30 mounted on the carriage It drives a pulley 31 connected to a counter shaft 32 through a pulley 33 and belt 3%. The shaft 32 in turn drives another shaft 35 through pulleys 36, 31 and a belt 38.

The ends of the shaft 35 carry disk 39to which are fastened levers 40. From the latter extend stub shafts ll which are received in bearings 42 carried respectively by the rods 1 I. Through the levers 48 and rods H, the disks 39 impart a sliding and tilting movement to the sander head on the bowling alley surface, as illustrated in Figure 5.

Suitable controls may be provided for governing the direction of the motor and the direction of the carriage it on the surface. The entire apparatus can be moved from one position to another by merely lifting the sander head and pushing it with the carriage. In lifting the sander head, the rods 55 may turn on the axis of the stub shaft 4 l and the rod It prevents the weight 8 from falling out if the head is inverted or nearly inverted.

If some point across the width of the surface requires more abrasive action, the weight 8 is merely moved to that point. The shifting of the weight may be accomplished automatically if desired by means of a level switch controlling an electric motor adapted to displace the weight by means of a screw shaft replacing the rod Ill.

Figure 8 shows an attachment to be applied to the sander for leveling off unusually high spots before the surface itself is sanded. The attachment consists of a pair of crossed legs 45 at each 7 end of the sander head and pivotally mounted on the rod H! or extensions thereof. Rollers 46 at the lower ends of the legs engage the floor. The upper end of one leg of each pair has a threaded rod 41 pivotally attached thereto and passed through the upper end of the adjacent member. The spacing of these ends is regulated by a nut 48 on the threaded end of the rod. By this means the distance of the sander head above the main surface may be regulated, and the sanding is performed in this position, while gradually lowering the head, until the rough spots are removed. Then the main surface may be sanded.

Although a specific embodiment of the invention has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is:

1. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, and means for oscillating said base on a surface.

2. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, means fixed to said base and engaging the top of said weight, and means for oscillating said base on a surface.

3. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, guide members extending transversely from the ends of said base and adapted to engage guiding surfaces, and means for oscillating said base on a surface.

4. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, means fixed to said base and engaging the top of said weight, guide members extending transversely from the ends of said base and adapted to engage guiding surfaces, and means for oscillating said base on a surface.

5. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, a carriage, and means on said carriage and connected to said base for oscillating said base on a surface.

6. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, and means for imparting an oscillating and tilting movement to said base on a surface.

7. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, a carriage, and means on said carriage and connected to said base for imparting an oscillating and tilting movement to said base on a surface.

8. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a weight slidably mounted on said base and adjustable transversely of the device, a carriage, a rotatable lever on said carriage, means for rotating said lever, and a rod fixed to said base and journalled to said lever.

9. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a pair of crossed legs pivotally attached to each end of said base and adapted to engage the working surface with their lower ends, means for adjusting the distance be tween the upper ends of each pair, whereby to adjust the distance of said bottom from said surface, and means for oscillating said base.

10. A device of the character described comprising a base having a convex bottom adapted to receive an abrasive, a pair of crossed legs pivotally attached to each end of said base and adapted to engage the working surface with their lower ends, a bolt extending from the upper end of one leg of each pair through the upper end of the opposite leg, a nut on each bolt to limit the spreading of said legs, whereby to adjust the distance of said bottom from said surface, and means for oscillating said base.

DAVID PRONOVOST. 

